Calculate the heat produced when 3.785 litre of actane `(C_(8)H_(18))` reacts with oxygen to form `CO` & water vapour at `25^(@)C`. The density of octane is 0.7025 gm/ml. enthalpy of combustion of `C_(8)H_(18)` is `-1302.7` k Cal/mol.
`{:(DeltaH_(f)^(@) CO_(2)(g)=-94.05" k Cal mol"^(-1),,,DeltaH_(f)^(@) CO(g)=-26.41" k Cal mol"^(-1),),(DeltaH_(f)^(@) H_(2)O(l)=-68.32" k Cal mol"^(-1),,,DeltaH_(f)^(@) H_(2)O (g)=-57.79" k Cal mol"^(-1)):}`

Answer

15.5528 M Cal

Explanation

`C_(8)H_(18)+25/2 O_(2) rarr 8 CO_(2) +9H_(2)O`
`DeltaH_(f)^(@)C_(8)H_(18) =-64.58`
`C_(8)H_(18) +17/2 O_(2) rarr 8 CO+9 H_(2)O`
`DeltaH=-666.73`
`DeltaH` for `3.785` litre of octane `=(666.73xx3.785xx0.7025xx10000)/(114)`
`15552.8" kCal"=15.5528" M kCal"`